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Biomedical subjects

Min Yao

Publications and source records attributed to Min Yao.

102 records · Page 6Linked to original sources
PubMed2003

[Complications in selective percutaneous coronary interventions: analysis of 2,868 cases].

OBJECTIVE: This report provides analysis of the complication rates, the risk factors, prevention and treatments of the complications of selective coronary interventions. METHODS: The types, the incidence, and the annual distribution characteristics of the complications in 2 868 cases of coronary interventions performed from October 1987 to December 2000 were reviewed, and the risk factors, prevention and treatments of the complications were analyzed. RESULTS: During the study period, 2 868 procedures of percutaneous coronary interventions (PCI) were performed. The total complication rate of PCI was 8.30% (6.33% - 20.00%). The procedure-related mortality rates were 0.07%. The complications included non-fatal Q wave myocardial infarctions (0.17%), coronary artery dissecting (2.58%), acute coronary artery occlusion (1.99%), coronary artery thrombosis (0.38%), coronary artery spasm (1.32%), coronary artery perforation (0.31%), severe arrhythmia (0.63%), severe contrast allergic reaction (0.07%), peripheral vascular complication (0.90%), and heart failure (0.10%). Emergent coronary artery bypass surgery (CABG) was required in 0.10% of the patients with PCI. The independent risk factors of the complications of PCI included unstable angina, coronary multivessel disease, and heart failure. CONCLUSIONS: The complication rates of PCI decreased with the accumulation of experiences. The complication rates in this group of patients are lower than the reported ones. This result is probably due to strictly selecting the indication, actively preventing and treating the complications.

Aged↗
PubMed2002

Structural analysis of an insect lysozyme exhibiting catalytic efficiency at low temperatures.

Bombyx mori lysozyme (BmLZ), from the silkworm, is an insect lysozyme. BmLZ has considerable activity at low temperatures and low activation energies compared with those of hen egg white lysozyme (HEWLZ), according to measurements of the temperature dependencies of relative activity (lytic and glycol chitin) and the estimation of activation energies using the Arrhenius equation. Being so active at low temperatures and low activation energies is characteristic of psychrophilic (cold-adapted) enzymes. The three-dimensional structure of BmLZ has been determined by X-ray crystallography at 2.5 A resolution. The core structure of BmLZ is similar to that of c-type lysozymes. However, BmLZ shows some distinct differences in the two exposed loops and the C-terminal region. A detailed comparison of BmLZ and HEWLZ suggests structural rationalizations for the differences in the catalytic efficiency, stability, and mode of activity between these two lysozymes.

Amino Acid Sequence↗
PubMed2002

The crystal structure of human MRP14 (S100A9), a Ca(2+)-dependent regulator protein in inflammatory process.

Human MRP14 (hMRP14) is a Ca(2+)-binding protein from the S100 family of proteins. This protein is co-expressed with human MRP8 (hMRP8), a homologue protein in myeloid cells, and plays an indispensable role in Ca(2+)-dependent functions during inflammation. This role includes the activation of Mac-1, the beta(2) integrin which is involved in neutrophil adhesion to endothelial cells. The crystal structure of the holo form of hMRP14 was analyzed at 2.1 A resolution. hMRP14 is distinguished from other S100 member proteins by its long C-terminal region, and its structure shows that the region is extensively flexible. In this crystal structure of hMRP14, Chaps molecules bind to the hinge region that connects two EF-hand motifs, which suggests that this region is a target-binding site of this protein. Based on a structural comparison of hMRP14 with hMRP8 and human S100A12 (hS100A12) that is another homologue protein, the character of MRP8/14 hetero-complex and the functional significance of the flexibility of the C-terminal region of hMRP14 are discussed.

Amino Acid Sequence↗
PubMed2002

Structure of the monomeric isocitrate dehydrogenase: evidence of a protein monomerization by a domain duplication.

NADP(+)-dependent isocitrate dehydrogenase is a member of the beta-decarboxylating dehydrogenase family and catalyzes the oxidative decarboxylation reaction from 2R,3S-isocitrate to yield 2-oxoglutarate and CO(2) in the Krebs cycle. Although most prokaryotic NADP(+)-dependent isocitrate dehydrogenases (IDHs) are homodimeric enzymes, the monomeric IDH with a molecular weight of 80-100 kDa has been found in a few species of bacteria. The 1.95 A crystal structure of the monomeric IDH revealed that it consists of two distinct domains, and its folding topology is related to the dimeric IDH. The structure of the large domain repeats a motif observed in the dimeric IDH. Such a fusional structure by domain duplication enables a single polypeptide chain to form a structure at the catalytic site that is homologous to the dimeric IDH, the catalytic site of which is located at the interface of two identical subunits.

Amino Acid Sequence↗
PubMed2002

The X-ray crystal structure of pyrrolidone-carboxylate peptidase from hyperthermophilic archaea Pyrococcus horikoshii.

The crystal structure of pyrrolidone-carboxylate peptidase (PCP) from hyperthermophilic archaea Pyrococcus horikoshii (PhoPCP) has been determined at 1.6-A resolution by X-ray crystallography. PCP belongs to the C15 family of cysteine protease, and specifically removes the amino terminal pyroglutamate residue from a wide range of N-terminal-blocking peptides. The crystal structure is very similar to that of other hyperthermophiles, Pyrococcus furiosus and Thermococcus litoralis, and even that from the mesophile, Bacillus amyloliquefaciens. The inter-subunit disulfide bonds, which have been proposed as one of the thermostabilizing factors of the PCP from such hyperthermophiles, was not present in PhoPCP. The result suggests that the thermostability of PhoPCP may be obtained by the accumulation of many weak factors.

Amino Acid Sequence↗
PubMed2002

Retrospective analysis of percutaneous transluminal coronary angioplasty and coronary stenting.

OBJECTIVE: To examine long-term efficacy of percutaneous transluminal coronary angioplasty (PTCA), coronary stenting and to assess the factors affecting its efficacy. METHODS: A total of 790 patients who underwent successful PTCA and PTCA + stent in this hospital were followed by direct interview or letter. The rate of follow-up was 84.2% and the period of follow-up was 0.9 - 12.7 (3.5 +/- 2.4) years. RESULTS: During follow-up, 4 (0.5%) patients died, 22 (2.8%) had nonfatal acute myocardial infarction, 10 (1.3%) had coronary artery bypass surgery, and 98 (12.4%) had repeat PTCA. The rate of recurrent angina pectoris was 31.1%. The cardiac event-free survival rate calculated by the Kaplan-Meier method was 88.2% at 1 year and 80.6% at 12.7 years. Cox regression analysis showed that there was a positive correlation between AMI history, stent implantation and the risk of cardiac events, and there was a negative correlation between the number of diseased arteries and the risk of cardiac events. Compared to the PTCA group, patients with PTCA + stent had significantly lower rates of total cardiac events. CONCLUSION: The long-term efficacy of PTCA, especially PTCA + stent in Chinese patients was very satisfactory, suggesting that PTCA + stent therapy should be the major treatment for revascularization in patients with coronary heart disease.

Adult↗
PubMed2002

[Experimental study on the inflammatory and immune responses of xenogenic acellular dermal matrix transplantation combined with thin split-thickness skin autograft].

OBJECTIVE: To investigate the dynamic process of the inflammatory response and the profile of Th1/Th2 cytokines after xenogenic acellular dermal matrix (ADM) transplantation with thin split-thickness skin autograft overlay. METHODS: SD rats were used in the study. In the control group, thin split-thickness skin autograft (STSG) was transplanted in the full-thickness skin defect of the SD rats; in the experimental group, the xenogenic acellular dermal matrix combined with thin split-thickness skin autograft was transplanted. The inflammatory response was examined histologically and Th1/Th2 cytokine mRNA expression in skin grafts was determined by reverse transcription-polymerase chain reaction. RESULTS: Inflammatory reaction was induced by ADM at the early stage of transplantation and decreased gradually. Th2 cytokine mRNA expression was higher in the ADM group than that of the control group whereas the Th1 cytokine mRNA expression was undetected in both groups. CONCLUSION: Xenogenic acellular dermal matrix is immunogenic. The increased expression of Th2 cytokines may be related to the humoral immune responses and the absence of ADM graft rejection.

Animals↗
PubMed2002

Detailed analysis of RNA-protein interactions within the bacterial ribosomal protein L5/5S rRNA complex.

The crystal structure of ribosomal protein L5 from Thermus thermophilus complexed with a 34-nt fragment comprising helix III and loop C of Escherichia coli 5S rRNA has been determined at 2.5 A resolution. The protein specifically interacts with the bulged nucleotides at the top of loop C of 5S rRNA. The rRNA and protein contact surfaces are strongly stabilized by intramolecular interactions. Charged and polar atoms forming the network of conserved intermolecular hydrogen bonds are located in two narrow planar parallel layers belonging to the protein and rRNA, respectively. The regions, including these atoms conserved in Bacteria and Archaea, can be considered an RNA-protein recognition module. Comparison of the T. thermophilus L5 structure in the RNA-bound form with the isolated Bacillus stearothermophilus L5 structure shows that the RNA-recognition module on the protein surface does not undergo significant changes upon RNA binding. In the crystal of the complex, the protein interacts with another RNA molecule in the asymmetric unit through the beta-sheet concave surface. This protein/RNA interface simulates the interaction of L5 with 23S rRNA observed in the Haloarcula marismortui 50S ribosomal subunit.

Amino Acid Sequence↗
PubMed2002

[An observation of the basement membrane remodeling after the combined grafting of xenogenic acellular dermal matrix with autoskin in rats].

OBJECTIVE: To observe the dynamic process of basement membrane remodeling after the combined grafting of xenogenic acellular dermal matrix with autoskin. METHODS: The rat skin wounds were covered with xenogenic porcine acellular dermal matrix overlaid with razor thin autoskin. The skin samples were collected at 1, 2, 3, 4, 8, 12 and 16 post-grafting weeks. The changes in laminin expression in the basement membrane and the ultrastructure of the basement membrane at 12 post-grafting weeks were observed by immunohistochemistry and transmission electron microscopy. The results were compared with those in simple thin autoskin grafting as the control. RESULTS: The laminin expression in the combined grafting was higher than that in control. At 12 post-grafting weeks, the basement membrane in combined grafting rats was clear and continuous and the hemidesmosome was relatively more in amount and distributed evenly. While in the autoskin group, the lamina densa in the basement membrane was blurred and discontinuous with a decrease in and uneven distribution of hemidesmosome. CONCLUSION: The increased expression of laminin in the basement membrane in the combined grafting rats might be beneficial to the remodeling of the basement membrane and to strengthening the connection of epithelium to the dermis, thus wound healing quality would be improved.

Animals↗
PubMedDate not supplied

An image retrieval system based on fractal dimension.

This paper presents a new kind of image retrieval system which obtains the feature vectors of images by estimating their fractal dimension; and at the same time establishes a tree-structure image database. After preprocessing and feature extracting, a given image is matched with the standard images in the image database using a hierarchical method of image indexing.

Abstracting and Indexing↗